Charge for fire extinguishers



March 1954 s. B. ANDERTON ET AL CHARGE FOR FIRE EXTINGUISHERS Filed June 7, 1951 SIDNEY 5. ANDERTON ER\c E. C. CAWOOD Patented Mar. 2, 1954 CHARGE "FOR FIRE EXTINGUISHERS SidneyrB. Anderton'and Eric-i1. 43.'Caw0od, Elland, England, -assig.nors' to Nun-Swift,- Limited, :El-

Jand, England -Applicationqlune *1, 1951, 'Scrial No. 230,286

The invention relates to 'fire extinguishers of the type in which a liquid is carried in a vessel or outer ?container having a discharge outlet and Within it (a) a sealed cartr-idge or equivalent container filled with a compressed or a "liquefied gas or with a gas-generating charge the release or the functioning of which, as the case may be, is operative to effect discharge of the liquid from the outer container, and b) a hermeticallysealed inner container filled witha foam producing or otheragent, the arrangement being such that when the gas charge is released or gen-- erated it functions by its pressure to unseal'the foam-producing or other agent and to propel such agent forcibly into the liquid in the outer container and to admix 'it intimately therewith before effecting any material discharge of the liquidfromthe extinguisher. The inner "container, in whic'h' the "foam-producing or other agent has been carried-has been made-of metal, and as such agentsareusually of such a:nature as to Iattackand corrode-ordinary metals it has been necessary to make the said inner container of a special non-corrodible metal, which has made the extinguisher, or rather the charge for an extinguisher, very expensive to produce. According to the present invention it is proposed'to construct'the inner container, in which aroam-pro'ducing or other agentis to "be carried, from a flexible inert plastic material. Such =a co'ntainercan be made of su'fiicient wall-thickness to enable it to :be handled when filled without fear of breakage but :such "that when in position within an extinguisher it will be ruptured "by the release -'or generation of the gas charge and its contents rapidly admixed, by the pressure of the released or generated gas, with the liquid in th'eouter container of the extinguisher.

The improved flexible inner container maybe in the form of a tube closed at one -end and adapted to be sealed at the otherend after filling. It may, however, be o'f anyother convenientshape or-form'.

The improved flexible inner container may be cclaims; 01.169 32;

In the accompanying drawings we haveshown in Fig. l more or less diagrammatically a lire extinguisher'of the type to which the invention relates; and in Fig. z-insectionalelevation one good, practical form -ofaa charge for such extinguisher embodying the invention.

In the drawings, a represen'ts a tube, which will be hereinafter termed the charge tube and which may be'made of suitable metal not necessar ilynon-corrodible. The upper end of the tube 7 axis fiangedoutwardly as at a to su port a carrier-ringb, and 'it is held'in position'withinan outer container '0 by means or a head d which forms a closure to the open upper end of the tube. V Supported within the upper end of the tube a by :being screwed into a central threaded ope-ningiin the'carrierring b is a container is for compressed or 'liquefied' gas, sealed atuits upper end by disc e adapted to be punctured by a piercer lbper'a'ble from the exterior of the head Below the gas container e there i provided within the tube a :a pad y of resilient material such asispon'gy rubber, the'upper side 'ofsuch ad being iurn'i'shed with a'wa'sh'er g of suitable material against which the lower extremity of the gas container e can abut. The pad g has accutral :operlill'g"g "through it of suitable diameter.

The lower extremit of the tube a is closedby a plate It having a central "opening h of suitable diameter, and resting on this plate is a pad i 'of suitable resilient material such as spongy rubber. Between the two resilient pads g and -z' thereis confined a sealed bag 7 composed of a flexible inert plastic material and adapted to contain'a ream-producing or other agent, the saidbag thus constituting as it were an inert lining to the pertion of the tube a Withinwhich-it is located. This is a featureof importance since the tube need not, if the agent with which thebag i is filled is of a corrosive nature, be made of non-corrodible and thus expensive metal.

When by the operation of the piercer f the sealing disce' of the gas container e is punctured to release the gas charge the space m in the upper part ofthe tubea above the pad 9" becomes filled with pressure gas and the pad is forced downwardly to expose the central opening 9 through the pad. The pressure gas thus passes into the space in the tube below the "pad and compresses the flexible bag a. "When the pressure on the "bag becomes suffi'ciently great the resilient-pad i *ben'ea'th the b'ottombf the bag is forced through the central opening h of the plate in and the bag is forced into contact with the periphery of the opening it and is thereby ruptured, the said periphery being preferably suitably serrated to assist in the rupturing of the bag.

When the bottom of the bag is ruptured the contents of the bag are discharged forcibly downwards into the liquid in the outer container of the extinguisher to become intimately admixed with it, and the liquid is expelled through the usual discharge pipe (2' and foam producing nozzle The two resilient pads g and 2' are useful in protecting the flexible bag 7' during transport and the pad i serves the further useful purpose of delaying the rupture of the bag until a pressure has been developed above it sufficient to ensure rapid expulsion of the contents of the bag when rupture takes place.

Whilst the constructional embodiment of the invention which has been described and illus trated is good and practical and is preferred, it is only given by way of example as there are other ways in which the invention can be carried into practice. The lower end of the tube 12 might for instance be formed as an open-work grid and the flexible bag 9' rest directly upon such grid. Such an arrangement would not, however, provide protection for the lower end of the bag during transport, and there would be a risk of the openings in the grid becoming clogged on rupture of the bag by the material of which the bag is composed and'thus preventing correct functioning of the extinguisher. In another arrangement the tube a might be perforated or reticulated say in its lower part in such manner that the pressure gas when released can force the bag into contact with the edges of the perforations or reticulations and thereby cause it to be ruptured. Neither of the alternative arrangements which have been mentioned present however the advantage of that which has been described and illustrated namely that the sealed flexible bag containing the foam-producing or other agent is protected against damage during transport.

, Having thus described our invention, what we claim as new and desire to secure by Letters Patent is:

1. In a fire extinguisher, means for discharging under pressure a foam-producing or other agent into the main body of said fire extinguisher,

comprising'in combination, a housing formed at one end thereof with an end wall formed with at least one opening therein communicating with the main bod of said fire extinguisher; puncturing means arranged in said end wall; a sealed gas cartridge mounted in said housing; a flexible container loosely arranged in said housing between said gas cartridge and said end wall of said housing so as to be easily removable therefrom and being formed of a flexible material inert to the agent contained therein; and means for opening said gas cartridge, whereby the pressure of the gas released by said cartridge upon the opening thereof will force said flexible container against said end wall and thereby rupture said flexible container forcing the contents thereof through said opening in said end wall into the main body of said fire extinguisher.

2. In a fire extinguisher, means fordischargring under pressure a foam-producing or' other agent into the main body of said fire extinguisher, comprising, in combination, a housing formed at one end thereof with an end wall formed with at least one opening therein communicating with the main body of said fire extinguisher; a sealed gas cartridge mounted in said housing; a flexible container loosely arranged in said housing between said gas cartridge and said end wall of said housing so as to be easily removable therefrom and being formed of a flexible material inert to the agent contained therein; puncturing means located on said end wall of said housing adjacent said opening therein; and means for opening said gas cartridge, whereby the pressure of the gas released by said cartridge upon the opening thereof will force said flexible container against said end wall and thereby rupture said flexible container forcing the contents thereof through said opening in said end wall into the main body of said fire extinguisher.

3. In a fire extinguisher, means for dischargingunder pressure a foam-producing or other agent into the main body of said fire extinguisher, comprising, in combination, a housing formed at one end thereof with an end wall formed with at least one opening therein communicating with the main body of said flre extinguisher; puncturing means arrangedon said end wall; a sealed gas cartridge mounted in said housing forming a space between the side walls of said housing and said gas cartridge; a flexible container loosely mounted in said housing between said gas cartridge and said end wall of said housing so as to be easily removable therefromand being formed of a flexible material inert to the agent contained therein; a resilient pad located between said gas cartridge and said flexible container and being formed with an opening contacting said gas cartridge which upon compression of said resilient pad allows said space between said side wall of said housing and said gas cartridge to communicate with said flexible container; and means for opening said gas cartridge, whereby the pressure of the gas released by said cartridge upon the opening thereof will force said flexible container against said end wall and thereby rupture said flexible container forcing the contents thereof through said opening in said end wall into the main body of said fire extinguisher.

4. In a fire extinguisher, means for discharging under pressure a foam-producing or other agent into the main body of said fire extinguisher, comprising, in combination, a housing formed at one end thereof with an end wall formed with a central opening therein communicating with the main body of said fire extinguisher; a sealed gas cartridge mounted in said housing forming a space between the side walls of said housing and said gas cartridge; a flexible container loosely arranged in said housing between said gas car.- tridge and said end wall of said housing adjacent said side walls thereof so as to be easily removable therefrom and being formed of a flexible material inert to the agent contained therein; puncturing means located on said end wall of said housing adjacent said opening therein; a resilient pad located between said gas cartridge and said flexible container and being formed with an opening contacting said gas cartridge which u on compression of said resilient pad allows said space between said side walls of said housing and said gas cartridge to communicate with said flexible container; and means for opening said gas cartridge, whereby the pressure of the gas released by said cartridge upon the opening thereof will force said flexible container against said endwall andthereby rupture said flexible con-f tainer forcing the contents thereof 'throughsaid opening in said end wall into the main body of said fire extinguisher.

5. In a fire extinguisher, means for discharging under pressure a foam-producing or other agent into the main body of said fire extinguisher, comprising, in combination, a housing formed at one end thereof with an end wall formed with a central opening therein communicating with the main body of said fire extinguisher, said end wall being formed with a serrated puncturing portion adjacent said central opening therein; a sealed gas cartridge mounted in said housing forming a space between the side walls of said housing and said gas cartridge; a flexible container loosely arranged in said housing between said gas cartridge and said end wall of said housing so as to be easily removable therefrom and being formed of a flexible material inert to the agent contained therein; a resilient pad located between said gas cartridge and said flexible container and being formed with an opening contacting said gas cartridge which upon compression of said resilient pad allows said space between said side walls of said housing and said gas cartridge to communicate with said flexible container; a second resilient pad located between said end wall of said housing and said flexible container separating said flexible container from said end wall; and means for opening said gas cartridge, whereby the pressure of the gas released by said cartridge upon the opening thereof will force said flexible container against said end wall and thereby rupture said flexible container forcing the contents thereof through said opening in said end wall into the main body of said fire extinguisher.

6. In a fire extinguisher, means for discharging under pressure a foam-producing or other agent into the main body of said fire extinguisher, comprising, in combination, a housing formed at one end thereof with an end wall formed with an opening therein communicating with the main body of said fire extinguisher; a sealed gas cartridge mounted in said housing forming a s ace between the side walls of said housing and said gas cartridge; a flexible container loosely arranged in said housing between said gas cartridge and said end wall of said housing adjacent said side walls thereof so as to be easily removable therefrom and being formed of a flexible material inert to the agent contained therein puncturing means located on said end wall of said housing adjacent said opening therein; a resilient pad located between said gas cartridge and said flexible container and being formed with an opening contacting said gas cartridge which upon compression of said resilient pad allows said space between said side walls of said housing and said gas cartridge to communicate with said flexible container; a second resilient pad of sponge rubber located between said end wall of said housing and said flexible container separating said flexible container from said end wall; and means for opening said gas cartridge, whereby the pressure of the gas released by said cartridge upon the opening thereof will force said flexible container against said end wall and thereby rupture said flexible container forcing the contents thereof through said opening in said end wall into the main body of said fire extinguisher.

SIDNEY B. ANDERTON. ERIC E. C. CAWOOD.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,588,234 Kauch et a1 June 8, 1926 2,346,183 Paulus et al Apr. 11, 1944 2,557,120 Knoblock June 19, 1951 2,557,162 Wetzel et al June 19, 1951 2,571,877 Henshaw Oct. 16, 1951 

